Pin-tumbler lock.



P. F. AUGENBRAUN.

PIN TUMBLER LOOK.

APPLICATION FILED DEC. 28, 1011.

Patented Mar. 19, 1912.

UNITED, sTATEs PATENT OFFICE.

PETER. F. AUGENBRAUN, OF STAMFORD, CONNECTICUT, ASSIGNOR TO THE YALE &TOWNE MANUFACTURING COMPANY, OF STAMFORD, CONNECTICUT.

PIN-TUMIBLER LOCK.

- To all whom it may concern RRAUN, a citizen of the I) Be it known thatI, PETER F. AUGEN- *nited States, residing at Stamford, in the county ofFairfield and Stateof Connecticut, have invented certain new and usefulImprovements in Pin- Tumbler Locks; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable other'sskilled in the art to which it appertains tomake and use the same.

by the bittings of the key, and as the tumblers engage the bittings ofthe key, the latter is'held against withdrawal. It is obvious that in alock of this type, every time a key is inserted and withdrawn, both" thetumblers andthe drivers are raised and lowered in their recesses, andthat when the key is pushed into place the tumblers tend to bear againstone side of the tumbler recess, and when the key is withdrawn,tend tobear against the other, and at the same time to move up and down withinthe recess. In

case of locks which are used very frequently,

this action results in considerable wear, andmay'after a time result inunsatisfactory, action of the tumblers. 7 My invention is intended toprotect the operating parts-of the lock against derangement owing towear from long and constant use, and it also results in making'the locksecure against attack by boring a hole along the edge of the plug at thejuncture of the tumbler recesses in the plug and the cy]- inder.

' The objects therefore of the present invention are first to prolongthe life of the lock,'and' second to add to the security of the lock. 5

With these and other objects in view, my invention consists in thedetails oiconstruction and combination of parts as will be claims.

" more fully described and pointed out in the A Specification of LettersPatent. Application fi led December 28, 1911 Serial No. 668,277.

Patented Mar. 19, 1912.

In the accompanying drawings, Figure 1.

is a view in longitudinal section of my improved lock; Fig. 2 is a viewin transverse section through Fig. 1; Fig. 3 is a similar view showingthe plug partly turned and the tumblers and drivers out of alinement;Fig. 4 is a view in elevation of the plug. Fig. 5 is a view 'inelevation of the plug and Fig. 6 asectional view of the cylinder,

showing. blocks having holes for the tumblers, instead of the bushingsshown in Figs. 1, 2 and 3.

1 represents the cylinder provided with a cylindrical bore for the plug2, which latter is cylindrical, and isprovided with a key way 3extending throughout its len th, and with an enlarged outer end .or 'heawhich rests in a counterbored, recess in the cylinder 1, flush orapproximately so with the outer face of the cylinder. The plug 2 isprovided with a seriesof recesses, the bottom of which are inopencommunication with the top of the key way 3 in the plug, so thatwhen a key is entered in the plugv it will engage the tumblers in theusual and well known 'manner. The recesses in the plug aline withsimilar recesses in the cylinder,

and the said recesses in both the plug and the cylinder "are linedwiththe steel or other hardened metal bushings 4 and 4, thus protectingthe'softer metal of the cylinder and plug from the abrading and wearingaction of the tumblers 5 and their drivers 6. The bushings 4F in thecylinder-may extend to the tops of the recesses and house the springs 7,"or they may extend a only far enough to 'cover the movements of thedrivers, while the bushin s 4 in the plug extend, preferably from t etop of the keyway 3 to the outer surface of the plug so as to meet orjoin the lower ends of the bushings in the,cylinder.

Instead of providing the plug with a series of recesses each lined witha hard metal" bushing as above de-' scribed, I may insert a steel block8 in the plug and a similar. block 8 in the cylinder, as shown in Figs.5 and 6, the two steel blocks, being each provided with a plurality ofrecesses for the tumblers.

By the use of the bushings or hardened bearings for the tumblers, thelife of the lock is prolonged, as the hardened surfaces cylinder and iprevent the wear due to the movements of the tumblers' and driversagainst the softer such bushings.

departing from the spirit and scope of my walls of the recesses. Thehardened bushings or blocks are a great protection to the security ofthe lock, as they prevent drilling along the edge of the plug in linewith the tumbler recesses, because a drill would be turned aside bythese hardenedbushings or blocks. N 0 hole, therefore, could be drilledin the line of the tumbler recesses, which is necessary for that methodof attack which endeavors to manipulate the tumblers by a thin piece ofsteel introduced into said drill holes.

In the drawings I show the bushings fitted to every tumbler recess, butthis is not essential, as benefit would result from the fitting of oneor more of the recesses with It is evident that many slight changesmight be resorted to in the relative arrangement of. parts shown anddescribed without invention. Hence I would have it understood thatI donot wish to confine myself to pin tumblers mounted to move in saidbearings.

2. In a-pin tumbler lock, the combination of a cylinder and plug eachhaving alined recesses, a hard metal bushing in each of said recesses,and pin tumblers located. and

moving within said bushings.

3. In a pin tumbler lock, a plug provided with a tumbler recess, and ahardened bushing fitted into said recess.

4. In a pin tumbler lock, a cylinder provided with a tumbler recess, anda hardened bushing fitted into said recess. 1 In testimony whereof, Ihave signed this specification inthe presence of two subscribingwitnesses.

v PETER F. AUGENBRAUN.

Witnesses l SCHUYLER MERRITT, EDITH M. CRoZIER.

30 bearings inserted in both of 'said parts, and v

